It is known that some specific multi-component room-temperature-curable silicone rubber compositions in the form of two separately stored compositions, the properties of which are not affected by atmospheric moisture, are widely used as sealing materials that possess excellent deep curability and allows uniform curing throughout the entire body of the sealing material, i.e., from the surface to the inner part. For example, Japanese Unexamined Patent Application Publication (hereinafter referred to as “Kokai”) S48-37452 discloses a two-package-type liquid room-temperature-curable silicone rubber composition comprising the following: a base composition composed of a filler and a diorganopolysiloxane capped at molecular terminals with silanol groups; and a catalyst composition consisting of an alkyl silicate, an amino-functional silane, and a curing catalyst. However, the silicone rubber obtained by curing the aforementioned room-temperature-curable silicone rubber composition is subject to deterioration of its long term adhesion durability against water. The reduction in adhesive properties and rubber-like characteristics is especially noticeable when the aforementioned silicone rubber is used in severe conditions, e.g., such as immersion in hot water.
In order to prevent the reduction in adhesive characteristics after immersion in hot water, it was proposed to use the aforementioned two-package type liquid room-temperature-curable silicone rubber composition with a curing agent in the form of 1,2-bis(trimethoxysilyl) ethane or 1,6-bis(trimethoxysilyl) hexane, or a similar disilylalkane composition and with an adhesion promoter in the form of a carbasilatrane compound (see Kokai S64-60656 and Kokai 2003-221506). However, the aforementioned multi-component room-temperature-curable silicone rubber compositions are characterized by a slow speed of curing and curability insufficient for use in fields such as manufacture of multiple-pane insulating glass units. In view of the above, it is desired to provide a multi-component room-temperature-curable organopolysiloxane that would combine good long term adhesion durability against water with rapid curing that would shorten production time.